What we commonly call “alcohol” is the chemical ethanol. The yeast enzyme zymase changes simple sugars in potatoes, corn or other cereals, or grapes into ethanol, which is found in:
How much is “a drink” of alcohol?
A standard drink is 12 grams of pure ethanol, which equals:
In other words, a can of beer contains as much ethanol as a shot of liquor. Malt liquor, which looks and tastes a lot like beer, contains 50% more ethanol per ounce than regular beer.